Novel hydrazinocarboxamide derivatives and preparation thereof

ABSTRACT

Alpha -Hydrazinocarboxamide and Alpha -( Alpha &#39;&#39;acylhydrazino)carboxamide derivatives of formula I   in which R1 and R2 each are lower alkyl or R1 and R2 together with the nitrogen atom to which they are joined form a piperidino or morpholino radical; R3 is hydrogen, lower alkanoyl, benzoyl, p-nitrobenzoyl, p-aminobenzoyl, p-chlorobenzoyl, isocyanoacetyl, or protected amino acyl radicals, for example, N-formylglycyl or   (N-carbobenzoxyglycylglycyl); R4 is lower alkyl, CHR7COOR8 or CH2CH2COOR8 wherein R7 is hydrogen or phenyl and R8 is hydrogen or lower alkyl; R5 is hydrogen or lower alkyl; or R4 and R5 together with the carbon atom to which they are joined form a cyclohexylidene radical; and R6 is a cyclohexyl or CHR9COY wherein R9 is hydrogen or benzyl and Y is hydroxyl, lower alkoxy or amino, with the provisos that when Y is hydroxyl then R8 is hydrogen, that when Y is lower alkoxy then R8 is lower alkyl and that when Y is amino R4 is lower alkyl, are disclosed herein along with the related Alpha -hydrazinocarboxamide and Alpha ( Alpha &#39;&#39;-acylhydrazino)carboxamide compounds of formula III   in which R1, R2, R3, R5 and R7 are as defined above and Y is lower alkoxy. These compounds possess antibacterial activity. Methods for their preparation and use are disclosed also.

United States Patent 1 Failli et al.

[ 1 June 10, 1975 NOVEL HYDRAZINOCARBOXAMIDE DERIVATIVES AND PREPARATION THEREOF [731 Assignee: American Home Products Corporation, New York, N.Y.

22 Filed: Feb. 7, 1973 211 App1.No.:330,359

[52] US. Cl. 260/l12.5; 260/247; 260/293.5I; 260/3265 FM; 260/471 C; 260/482 P;

[51] Int. Cl. C07c 103/52; A61k 27/00 [58] Field of Search 260/112.5, 561 H, 561 A, 260/562 H, 566 B, 558 H, 558 R, 247,

293.51, 326.5 F, 226.5 FM, 471 C, 482 P [56] References Cited UNITED STATES PATENTS 3,072,713 l/1963 Gutmann 260/558 H 3,162,680 12/1964 Biel..- 260/558 H OTHER PUBLICATIONS Ugi, 1., lsonitrile Chemistry, Academic Press, New York, 1971, pp. 159-161, QD305.N7.18. 1. Ugi, Newer Methods of Preparative Organic Chemistry, W. Foerst, ed., v.1\/, Academic Press, NY. (1968), p. 30.

Primary Examiner-Lewis Gotts Assistant ExaminerRegina1d .1. Suyat 57 ABSTRACT a-Hydrazinocarboxamide and a-(a'-acylhydrazino)- carboxamide derivatives of formula 1 in which R and R each are lower alkyl or R and R together with the nitrogen atom to which they are joined form a piperidino or morpholino radical; R is hydrogen, lower alkanoyl, benzoyl, p-nitrobenzoyl, paminobenzoyl, p-chlorobenzoyl, isocyanoacetyl, or protected amino acyl radicals, for example, N- formylglycyl or COCH NHCOCH NHCOOCH Q (N-carbobenzoxyglycylglycyl); R is lower alkyl, CHRCOOR or CH CH COOR wherein R is hydrogen or phenyl and R is hydrogen or lower alkyl; R is hydrogen or lower alkyl; or R and R together with the carbon atom to which they are joined form a cyclohexylidene radical; and R is a cyclohexyl or CHR COY wherein R is hydrogen or benzyl and Y is hydroxyl, lower alkoxy or amino, with the provisos that when Y is hydroxyl then R is hydrogen, that when Y is lower alkoxy then R is lower alkyl and that when Y is amino R is lower alkyl, are disclosed herein along with the related a-hydrazinocarboxamide and a-(a-acylhydrazino)carboxamide compounds of formula 111 in which R, R R, R and R are as defined above and Y is lower alkoxy. These compounds possess antibacterial activity. Methods for their preparation and use are disclosed also.

8 Claims, No Drawings NOVEL HYDRAZINOCARBOXAMIDE DERIVATIVES AND PREPARATION THEREOF BACKGROUND OF THE INVENTION 1. Field of Invention This invention relates to novel a-hydrazinocarboxamide and oz-(a'-acylhydrazino)carboxamide derivatives, to processes for their preparation and to their use as intermediates for the preparation of related derivatives.

2. Description of the Prior Art Only within the last 10 years has some attention been focused on a-hydrazinocarboxamides. This attention resulted from a chemical investigation by I. Ugi and F. Bodesheim, Justus Liebigs Ann. Chem., 666, 61 (1963). In this particular investigation a-(a, B'-diacylhydrazino)-carboxamides were prepared by the a-addition of acylhydrazones and carboxylic acids to isonitriles. The carboxamides of this latter study are readily distinguished from the compounds of the present invention by their lack of a basic nitrogen.

Indeed, the successful preparation of the present oz-(hydrazino)- and a-(oz'-acylhydrazino)carboxamides from hydrazones, acids and isonitriles is somewhat unexpected and surprising in light of a recent comment by Ugi. More explicitly, in Newer Methods of Preparative Organic Chemistry, Vol. IV, N. Foerst, Ed., Academic Press, New York and London, 1968, p. 28, Ugi states that the lower basicity of the a-nitrogen in a hydrazone system has an adverse influence on a-additions involving hydrazones and it may be assumed that such reactions can rarely be used for preparative purposes.

SUMMARY OF THE INVENTION The oz-hydrazinocarboxamide derivatives of the present invention may be represented by Formula 1,

R N N E NHR R A R o in which R and R each are lower alkyl or R and R together with the nitrogen atom to which they are joined form a piperidino or morpholino radical; R is hydrogen, lower alkanoyl, benzoyl, p-nitrobenzoyl, paminobenzoyl, p-chlorobenzoyl, isocyanoacetyl, or protected amino acyl radicals, for example, N- formylglycyl or COCH NHCOCH NHCOOCH (N-carbobenzoxyglycylglycyl); R is lower alkyl, CI-IR COOR orCH CH COOR wherein R is hydrogen or phenyl and R is hydrogen or lower alkyl; R is hydrogen or lower alkyl; or R and R together with the carbon atom to which they are joined from a cyclohexylidene radical; and R is a cyclohexyl or CHR COY wherein R is hydrogen or benzyl and Y is hydroxyl, lower alkoxy or amino, with the provisos that when Y is hydroxyl then R is hydrogen, that when Y is lower alkoxy then R is lower alkyl and that when Y is amino R is lower alkyl.

In one aspect of this invention the preparation of the compounds of formula 1 involve a key reaction wherein a hydrazone of formula II in which R ,R and R are as defined hereinbefore and R is lower alkyl, CI-IRCOOR or CI-I CH COOR wherein R is as defined hereinbefore and R is lower alkyl or R or R together with the carbon atom to which they are joined from a cyclohexylidine radical, is treated with an acid of formula R)( in which R is as defined hereinbefore and when R is hydrogen, R and X together represent an inorganic acid ionizable to provide a proton. and when R is other than hydrogen as defined hereinbefore X represents a hydroxyl, in the presence of an isonitrile of formula R NC in which R is cyclohexyl or CHR COY wherein R is as defined hereinbefore and Y is lower alkoxy to obtain the corresponding compound of formula I In another aspect of this invention compounds of formula I in which R, R R and R are as defined in the first instance, R is CI-IRCOOR in which R is as defined hereinbefore and R is lower alkyl and R is CH COY in which Y is lower alkoxy are transformed to 2,5-dioxopyrrolidines of formula III either spontaneously during the formation of said latter compounds of formula I or by subjecting said latter compounds of formula I to alkaline conditions.

HI (Y lower alkoxy) DETAILED DESCRIPTION OF THE INVENTION The term lower alkyl as used herein contemplates straight chain alkyl radicals containing from one to six carbon atoms and branched chain alkyl radicals containing three to four carbon atoms and includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl and the like.

The term lower alkanoyl as used herein contemplates both straight and branched chain alkanoyl radicals containing from one to six carbon atoms and in- 3 cludesformyl, acetyl, propionyl, hexanoyl and the like.

The term lower alkoxy" as used herein contemplates both straight and branched chain alkoxy radicals containing from one to six carbon atoms and includes methoxy, ethoxy, propoxy, hexyloxy and the like.

It will be noted that the structure of the compounds of this invention includes asymmetric carbon atoms. It is to be understood accordingly that the isomers arising from this asymmetry are included within the scope of this invention. Such isomers are obtained by classical separation techniques and by sterically-controlled synthesis.

The compounds of formula I of this invention exhibit utility as antibacterial agents against a number of microorganisms, for example, Pseudomonas aeruginosa, Proteus mirabilis, Proteus vulgaris, Klebsiella pneumoniae and Serratia marcescens, in standard tests for antibacterial activity, such as those described in Antiseptics, Disinfectants, Fungicides and Sterilization, G. F. Reddish, Ed., 2nd ed., Lea and Febiger, Philadelphia, 1957 or by D. C. Grove and W. A. Randall in Assay Methods of Antibiotics, Med. Encycl. Inc., N.Y.

For example, a test like the serial broth dilution, see Grove and Randall, cited above, in which dilutions of the compounds of this invention in nutrient broth are inoculated with the microorganisms or fungi, described above, incubated at 37C.for 2 days, respectively, and examined for the presence of growth, shows that 3[N- (dimethylamino)formamido]-3-methyl-2,5-dioxo-1- pyrrolidineacetic acid ethyl ester (Example 27) is able to inhibit growth totally in this system of Proteus vulgaris, Klebsiella pneumoniae and Serratia marcescens at a concentration of 100 meg/ml. or less.

When the compounds of formula I are employed as antibiotic or antifungal agents in warm-blooded animals, e.g. rats, they may be administered alone or in combination with pharmacologically acceptable carriers. The proportion of the compound is determined by the solubility and chemical nature of the compound, chosen route of administration and standard biological practice. For example, they may be administered orally in solid form containing such excipients as starch, milk sugar, certain types of clay and so forth. They may also be administered orally in the form of solutions or they may be injected parenterally. For parenteral administration they may be used in the form of a sterile solution containing other solutes, for example, enough saline or glucose to make the solution isotonic.

The dosage of the present compounds as antibiotic agents will vary with the form of administration and the particular compound chosen. Furthermore, it will vary with the particular compounds chosen. Furthermore, it will vary with the particular host under treatment. Generally, treatment is initiated with small dosages substantially less than the optimum dose of the compound. Thereafter, the dosage is increased by small increments until the optimum effect under the circumstances is reached. In general, the compounds of this invention are most desirably administered at a concentration level that will generally afford antibacterially or antifungally effective results without causing any harmful or deleterious side effects and preferably at a level that is in a range of from about 1.0 mg to about 1000 mg. per kilo per day, although as aforementioned variations will occur. However, a dosage level that is in the range of from about mg to about 500 mgper kilo per day is most desirably employed in order to achieve effective results."

In addition, the said ultimate products may be employed topically. For topical application they may be formulated in the form of solutions, creams, or lotions in pharmaceutically acceptable vehicles containing 0.] 5 per cent, preferably 2 per cent, of the agent and may be administered topically to the infected area of the skin.

Also the antibacterial properties of the said ultimate products may be utilized for washing equipment in hospitals, homes and farms, instruments used in medicine and bacteriology, clothing used in bacteriological laboratories, and floors, walls and ceilings in rooms in which a background free of gram-positive and gramnegative microorganisms, such as those listed above, is desired. When employed in this manner the said ultimate products are formulated in a number of compositions comprising the active compound and an inert material. In such compositions, while the said ultimate products may be employed in concentrations as low as 500 p.p.m., from a practical point of view, it is desirable to use from about 0.1% to about 5% by weight or more.

The formulations that may be used to prepare antiseptic wash solutions of the compounds of this invention are varied and may readily be accomplished by standard techniques, see for example, Remingtons Practice of Pharmacy, E. W. Martin et al., Eds., 12th ed., Mack Publishing Company, Easton Penn, 1961, pp. 1 121 1 150. In general, the said ultimate products are made up in stock solutions. They can also be formulated as suspensions in an aqueous vehicle. These make useful mixtures for decontaminating premises. Also, aqueous vehicles containing emulsifying agents, such as sodium lauryl sulfate, and relatively high concentrations, e.g., up to about 5% by weight, of the compounds may be formulated by conventional techniques.

A typical antiseptic preparation useful for disinfecting floors, walls, ceiling, and articles in a contaminated room may be prepared by adding 5 to 25 g. of 3-[N- (dimethylamino )formamido -3-methyl-2 ,5 -dioxo-1- pyrrolidineacetic acid ethyl ester to a mixture of to 300 g of polyethylene glycol 1540 and 150 to 300 g of polyethylene glycol 300. The resulting mixture is stirred while a solution of 1 to 10 g of sodium lauryl sulfate in 300 to 400 ml of water is added portionwise. The article to be disinfected is coated or immersed in the preparation for a prolonged time, for example, 1 hour, and then rinsed with sterile water.

In addition, the compounds of formula I exibit trichomonacidal activity against certain Trichomonas species, for example, Trichomonas vaginalis. A demonstration of this activity is readily achieved in standard tests for trichomonacidal activity; for example, see R. J. Schnitzer in Experimental Chemotherapy," Vol. I, R. J. Schnitzer and F. Hawking, Ed., Academic Press, N.Y., 1963, p. 289.

When the compounds of formula I are employed as trichomonacidal agents they may be administered in the same manner described above for their application as antibacterial agents.

Likewise, the 2,5-dioxopyrrolidines of formula III exhibit a similar degree of the antibacterial and trichomonacidal activities, described above. Accordingly, they may be used for this purpose in the same manner as described for the compounds of formula I.

In practising the process of this invention three classes of starting material are required; namely, hydrazones of formula II, acids of formula RX and isonitriles of formula R NC.

The requisite hydrazones of formula II are prepared by condensing an appropriately substituted hydrazine of formula RR NNI-I in which R and R are as defined in the first instance, with a carbonyl compound of formula R R CO in which R is lower alkyl, CHR COOR or CI-I CI-l COOR wherein R is hydrogen or phenyl and R is lower alkyl'and R or R and R together are as defined hereinbefore.

Hydraines of formula R R NNI-l are either known for example, 1, l dimethyl hydrazine, N- aminopiperidine, N-aminomorpholine, or they are prepared by known methods; for example, see E. Miiller in Methoden der Organischen Chemie, Houben- Weyl, E. Miiller, Ed., Vol. 10/2, Georg Thieme Verlag, Stuttgard, 1967, p. 50.

Likewise, the carbonyl compounds of formula R R CO are known and most are commercially available, for example, ethyl acetoacetate, isobutyraldehyde and cyclohexanone, or are prepared by known methods; for example, see P. Karrer, Organic Chemistry, 2nd ed., Elsevier Publishing Co., Inc., N.Y., 1946, p. 149.

The condensation of the hydrazine of formula RR NNI-I and the carbonyl compound of formula R R CO is preferably carried out in an inert solvent at an elevated temperature, at or near the reflux temperature of the mixture. Either an anhydrous, waterimmiscible hydrocarbon solvent, for example, benzene or toluene, with concomitant physical removal of water as it is being formed, e.g. by means of a Dean-Stark water separator, or a lower alkanol solvent, for example, ethanol, propanol or isopropanol may be employed. Thereafter, evaporation of the solvent and purification of the residue, for example, by distillation or crystallization, yields the corresponding hydrazone of formula II.

The acids of formula R X are known and are commercially available and include the inorganic acids, hydrochloric, sulfuric, phosphoric, hydrobromic acid and the like, or the organic acids, formic, acetic, benzoic, p-nitrobenzoic and the like.

The requisite isonitriles of formula R NC also are known, for example, cyclohexyl isonitrile [(I. Ugi and R. Meyr, Ber., 93, 239 (1960)]and ethyl isocyanoacetate [R. Appel et al., Angew. Chem., Int. ed., 10, 132 (1971 )1, or are easily prepared by known methods, for example, see P. Hoffman, et al., in Isonitrile Chemistry, Organic Chemistry, Vol. 20, I. Ugi, Ed., Academic Press, N.Y., 1971, p. 9.

Next, in a key reaction of the process of this invention, the aforementioned hydrazone of formula II is condensed with the acid of formula R')(, and the isonitrile of formula R NC, described above, to yield the corresponding compounds of formula I.

Although not critical it is preferable to use approxi mately equimolar amounts of the three requisite starting materials, for this condensation, The condensation is effected most conveniently in an inert solvent, for example, halogenated hydrocarbons including methylene dichloride, chloroform, and carbon tetrachloride, ethers and cyclic ethers including dioxane, diethyl ether and tetrahydrofuran, or lower aliphatic alcohols including methanol, ethanol and propanol. However,

when the three starting materials are mutually soluble or the mixture thereof becomes liquid during the course of the condensation the solvent may be omitted without any deleterious effects.

The temperature and duration of the condensation also are not critical. The reaction may be performed at temperatures ranging from 20 to C.; however, a range from 10 to 40C is most convenient, with room temperature to the boiling point of the solvent employed being preferred. The reaction time varies widely and depends on the reactivity of the various starting materials; however, reaction times from 15 minutes to several days are employed generally, with 6 hours to two days being preferred.

Thereafter the product is isolated and purified according to standard procedures. For instance the product is extracted with a water-immiscible solvent and, if needed, purified by chromatography and crystallization.

In this manner there are obtained the compounds of formula I in which R, R R and R are defined in the first instance, R is lower alkyl, CHRCOOR or CI-I CHOOOR wherein R is hydrogen or phenyl and R are lower alkyl or R and R together with the carbon atom to which they are joined form a cyclohexylidene radical, and R is cyclohexyl or CI-IR COY in which R is as defined hereinbefore and Y is lower alkoxy.

As noted hereinbefore the compounds of formula I in which R, R R and R are as defined in the first instance, R" is CHR COOR in which R is as defined hereinbefore and R is lower alkyl and R is CHR COY in which R is hydrogen and Y is lower alkoxy are transformed to the corresponding 2,5-dioxopyrrolidines of formula III. This transformation takes place spontaneously to some extent l080%) during the course of the condensation of the hydrazone of formula R R NN C(R )CH COOR in which R, R and R are as defined herein and R is lower alkyl, with a lower alkyl ester of isocyanoacetic acid and an acid of formula R X as defined herein under the conditions described above for such conden'sations. The mixture of the corresponding products of formulae I and III obtained under these conditions may be separated by crystallization or chromotagraphy on silica gel. If desired, the mixture is readily converted totally to the corresponding compound of formula III by treating the mixture with a base, for example, the alkali metal carbonates including sodium or potassium carbonate or the alkali metal hydroxides including sodium or potassium hydroxide in an inert solvent, for example, chloroform, benzene, tetrahydrofuran or ethanol. Completion of this conversion under alkaline conditions is achieved usually at temperatures ranging from 20 to 100C, preferably 50 to 60C., and reaction times of from 10 minutes to 6 hours, preferably 1 to 2 hours.

The compounds of formula I in which R is CHRCOOR or CH CI'I COOR wherein R is as defined hereinbefore and R is hydrogen and R is CHR COY in which R is as defined hereinbefore and Y is hydroxyl, mainly, the corresponding acid derivatives of the aforementioned esters, are obtained by treatment of said corresponding esters with a hydrolyzing agent. Generally speaking, this conversion is most conveniently performed by employing a base as the hydrolyzing agent, although hydrolysis under acidic conditions is also applicable. It should be noted herein that when compounds of formula 1 in which R is CHR COOR in which R is lower alkyl and R is CH COY is which Y is lower alkoxy are subjected to the above hydrolyzing conditions a mixture of the corresponding diacid and 2,5-dioxopyrrolidine of formula III results.

For basic hydrolysis a preferred embodiment involves subjecting the lower alkyl ester to the action of a strong base, for example, sodium or potassium hydroxide, in the presence of sufficient water to effect hydrolysis of the ester. The hydrolysis is performed using a suitable solvent, for example, methanol or ethanol.

The reaction mixture is maintained at a temperature of from C to the reflux temperature until hydrolysis occurs. Usually from 10 minutes to 6 hours is sufficient for this hydrolysis. The reaction mixture is then rendered acidic with an acid, for example, acetic acid, hydrochloric acid, sulfuric acid and the like, to obtain the corresponding free acid.

The compounds of formula I in which R is lower alkyl and R is CHR COY in which R is a defined hereinbefore and Y is amino are obtained by treatment of the corresponding lower alkyl esters, described above, with ammonia according to standard amidation methods. Preferred conditions for this amidation include treatment of the appropriate ester of formula I with a saturated solution of ammonia in an inert solvent, for example, methanol, ether or tetrahydrofuran at 0 to C for 6 hours to five days.

The compounds of formula I in which R is paminobenzoyl are obtained by treating the corresponding compounds of formula I, described above, in which R is p-nitrobenzoyl with a reducing agent. In this case the use of hydrogen in the presence of a noble metal catalyst, for example, palladium, platinum and the like in a hydrogenation apparatus is a preferred and convenient method.

Finally, the compounds of formula I in which R is isocyanoacetyl (COCH NC) are prepared directly from the aforementioned, corresponding compounds of formula I in which R is N-formylglycyl. This transformation is effected readily with dehydrating agents known to be effective for transforming known formamides to corresponding isonitriles, see P. Hoffman, et. al., cited above. A preferred method in this case is the use of phosgene in the presence of triethylamine.

The following examples illustrate further this invention.

EXAMPLE 1 Ethyl Levulinate Dimethyl Hydrazone A mixture of 21.5 g (0.15 mole) of ethyl luvulinate and 15.0 g (0.25 mole) of anhydrous dimethylhydrazine in 35 ml of ethanol is heated at reflux for 4 hours. The solvent is removed and the residue fractionally distilled. The title compound is collected, b.p. 98-100C/l5 mm., nmr (CDC1 6 1.25 (t, .l=7, 3H), 1.95 (3H), 2.40 (6H), 2.53 41-1), 4.13 (g, J=7,2H).

In the same manner but replacing ethyl levulinate with an equivalent amount of ethyl acetoacetate, ethyl acetoacetate dimethyl hydrazone, b.p. 8892C/ 1920 mm, v a 3245, 3180 and 1728 cm", is ob tained.

Similar replacement of the ethyl leulinate with ethyl a-phenylacetoacetate give ethyl a-phenylacetoacetate dimethyl hydrazone, b.p. 138-l43C/5 mm, nmr

(CDC1 8 1.13 and 1.30 (2:, J 7, 3H), 1.47 (3H), 1.56(3H), 1.86 (3H).

Similar replacement of the ethyl levulinate with cyclohexanone gives cyclohexanone dimethyl hydrazone, b.p. 82C/25 mm, nmr (CDCI 6 1.66 (6H), 2.43 (10H).

Similar replacement of the ethyl levulinate with 2-oxocyclohexanecarboxylic acid ethyl ester gives 2-oxocyclohexanecarboxylic acid ethyl ester dimethyl hydrazone, b.0. 132C/ 11mm.

EXAMPLE 2 3-(Piperidinoimino)butyric Acid Methyl Ester A mixture of methyl acetoacetate (13 g, 0.10 mole) and l-aminopiperidine (15 g, 0.15 mole) in absolute ethanol (30 m1) is heated at reflux for 4 hr. The solvent is removed and the residue fractionally distilled. The title comound has b.p. l25126C/13 mm.

In the same manner but replacing l-aminopiperidine with an equivalent amount of l-aminomorpholine, 3- (morpholinoimino)butyric acid ethyl ester, b.p. l50l52C/20 mm, v a 3240, 3180, 1720, 1640, 1600 cm is obtained.

In the same manner but replacing ethyl acetoacetate with an equivalent amount of cyclohexanone, l-(cyclohexylideneamino)piperidine, b.p. l24-217C/- 15-18 mm, is obtained. Reported b.p. for this compound is 76C/0.4 mm, H. Boehlke and W. Kliegel, Arch. Pharm. 229, 245 (1966).

EXAMPLE 3 Isobutyraldehyde Dimethyl Hydrazone A solution is isobutyraldehyde (43 g, 0.6 mole) and dimethylhydrazine (60 g, 1.0 mole) in benzene (500 ml) is heated at reflux temperature for 5 hr. using a Dean-Stark apparatus to collect the water. The solution is evaporated and the residue fractionally distilled. The hydrazone is obtained as a yellow oil, b.p. C, u ""1610,1475, 1450 cm.

In the same manner but replacing isobutyraldehyde with an equivalent amount of isovaleraldehyde, isovaleraldehyde dimethyl hydrazone, b.p. l45l49C is obtained.

Similar replacement of the isobutyraldehyde with an equivalent of propionaldehyde or hexaldehyde gives propionaldehyde dimethyl hydrazone and hexaldehyde dimethyl hydrazone, respectively.

EXAMPLE 4 2-Isocyano-3-phenylpropionic Acid Methyl Ester A solution of phosgene (5.2 g, 0.052 mole) in dry methylene chloride (45 ml) is added dropwise to a stirred solution of N-formylphenylalanine methyl ester (10.0 g, 0.048 mole) and l-methylmorpholine (13 g, 0.125 mole) in dry methylene chloride (25ml) at 30c. After completion of the addition the filtrate is concentrated under reduced pressure at room temperature. Benzene is added to the residue followed by filtration and concentration of the resulting solution. The residue is distilled to afford the title compound as a yellow oil, b.p. 97C/0.3 mm, v f a 2150, 1746, 1595, 1578, 1489, 694 cm.

The starting material, N-formylphenylalanine methyl ester, is known; see R. G. Jones, J. Amer. Chem. Soc., 71, 644 (1949) for DL-form and F. Bergel, et al., J. Chem. Soc., 3802 (1962) for L-form.

dimethyl hydrazone (17.1 g), described in Example 3,

and the isonitrile of formula R NC, ethyl isocyanoacetate (16.0 g), on 50 ml of anhydrous methanol containing 20 g. of hydrated alkali-aluminium silicate (Molec- Abstr, 63, 18260 (1965)], 2-isocyano-4- 5 ular Sieves No. 4), cooled to C. The mixture is stirred methylthiobutyric acid ethyl ester, b.p. 77-79C/ 0.1 at room temperature until completion of the condensais obtained. tion. [In this case the condensation is complete after 24 EXAMPLE hr. as determmed by tlc us1ng s1l1ca gel plates and a solvent system conslstmg of ethyl acetate-methanol N-Cyclohexyl-3-(dimethylaminoformamido)-3- (9:1)]. The mixture is filtered and concentrated. The methylglutaramic Acid Ethyl Ester Rland 3, residue is subjected to chromatography on silica gel. R3 R4 CH2CH2COOC2H5, R5 3 and R6 Elution with ethyl acetate-methanol (9: 1) give the title y y compound, nmr (CDCl a 0.91 and 1.02 (2d, J=6.5, A solution of the hydrazone of formula 11, ethyl levu- (t, J=7i (3H), (m, linate dimethyl hydrazone 9.39 g, 0.05 111016 de- 1H), 3944 f 1 11, L (7 7, scribed in Example 1, and the isonitrile of formula (3016-62017) R NC, cyclohexyl isonitrile (5.45 g, 0.05 mole), in 10 ml of dry methylene dichloride is cooled in an ice bath EXAMPLE 7 and treated dropwise with the acid of formula R X, for- N-[(N-Dimethylamino)-DL-valyl]glycine Ethyl Ester mic acid (2.35 g, 0.05 mole). The mixture is stirred for (1, R and R CH R H, R CH(CH R H 20 minutes in the cold and then stirred at room temperand R CH COOC H ature j f l of i g fi s thls A solution of the hydrazone of formula II, isobutyral- F the ensatlc comp g F 1;?" dehyde dimethylhydrazone (19.6 g, 0.172 mole) demmed by thm layer chromatograp C) usmg S1 lea scribed in Example 3, water (17.2 ml), and methanol gel plates and a Solvent System Fonslsimg (28.6 ml) is stirred at ice-bath temperature. After 5 efihyl T ream muted min., 12N 1101 145 ml) is added slowly. After an addiwlth 4N Sodlum hyqroxldi i wlthlethyl tional 2 min. the isonitrile, ethyl isocyanoacetate (19.4 i Thesgtractdls was e gi i ig g, 0.172 mol) is added. The solution is stirred at room dned M 1 g yle g 3 .3 temperature for 1.5 hr. The solution is diluted with The resldue. 1S crysta. 126 mm 2f 1 8 methylene chloride (500 ml), and washed with 4N ggf Yleld the compo 3 Nl-LOH 100 ml), water 50 ml), and a saturated SOlU- 3 3455 3340 1507 cm tion of sodium chloride (100 ml). The organic phase is EX MPLE 6 dried-(Na SO and concentrated. The organge oil is d' t'll ld th t' b. 124C 0.1 N-{[N-(Dimethylamlno)-N-(N-formylgylcyl)]-Dled 8112: p -1 l 1 1} 1 cine Eth lEster 1 R and R =CH R 3 Va y g y y 4 H R5 H 1 R6 By followmg the procedure of Example 5, 6 or 7 and COCH2NHCHO C a an T using the appropriate hydrazone of formula 11, acid of 2 2 5) formula R X and isonitrile of formula R NC then other The acid of formula R X,N-formylglycine (15.4 g), 40 compounds of formula I are obtained. Examples of described by R. S. Tipson and B. A. Pawson, J. Org. such compounds of formula 1 are listed in Table 1 to- Chem., 26, 4698 (1961 is added dropwise to a solugether with the hydrazone, acid and isonitrile required tion of the hydrazone for formula 11, isobutyraldehyde for their preparation.

TABLE 1 Hydrazone Acid of lsonitrile Product of Ex. of Formula 11 Formula R3X (RNC) Formula 1 8 ethyl acetoformic acid cyclohexyl N-cyclohexyl-3-(dimethylacetate diisonitrile aminoformamido)-3- methyl hydramethylsuccinamic acid zone ethyl ester, m.p. 79.5

81C, 1728, 1668 cm. 9 ethyl levulibenzoic acid cyclohexyl N-cyclohexyl-4-[N-(dinate dimethyl isonitrile methylamino)benzamido]- hydrazone 4-methylglutaramic acid ethyl ester, my. 79 805C, 14M," "'3 1728, 1665, 1650 cm. 10 ethyl acetoformic acid 2-isocyano-3- N-(a-carboxyphenethyhacetate diphenylpro- 3-[N-(dimethylamino)- methyl hydrapionic acid formamido1-3-methylzone methyl ester succinamic acid ethyl (described in N-methyl diester, m.p. (Example 4) 91 109C, nmr (CDCl;,) 6 1.24 l= 7,3H), 2.78 (61-1), 2.82 (111,211), 3.17 (d, J=6.5, 2H) 1 l isobutyralformic acid 2-isocyano-3- N-lN-(dimethylamino)-N- dehyde diphenylproformylDL-valyl]phcnylmethyl hydrapionic acid alanine methyl ester, zone methyl ester v f a 1735, 1640-1660cm l2 cyclohexanone formic acid 2-isocyan0-3- N- {l-[N-(dimethylamino)- dimethyl hydraphenylproformamidolcyclohexylzone pionic acid carbonyl}phenylalanine methyl ester methyl ester, mp.

13 EXAMPLE 27 3-[N-(Dimethylamino)formamido]-3-methyl-2,5- dioxo-l-pyrrolidineacetic acid ethyl ester (1 l l; R and R CH R C1-10, R =CH and R 1-1) mixture is diluted with ethyl acetate (200 ml) and 4N l5 N11 Ol-1 (100 ml). The organic layer is separated, washed with water, dried (MgSO and concentrated under reduced pressure. The oily residue is crystallized from hexane-methylene chloride to give the title compound, m.p. 89 92C., v 'z 1785, 1740, 1715,

EXAMPLE 28 3-(p-Chloro-N-piperidinobenzamido)-3-methyl-2,5-

dioxo-l-pyrrolidineacetic acid ethyl ester (1 l l; R and R (CH- R p-chlorophenyl, R =C1-l and R A solution of the hydrazone of formula 11, ethyl acetoacetate piperidinehydrazone (21.2 g, 0.1 mole), ethyl isocyanoacetate (l 1.3 g, 0.1 mole) chlorobenzoic acid (15.6 g, 0.1 mole) in dry methylene and pchloride ml) are stirred at reflux temperature for 7 days. The solution is diluted with methylene chloride (50 ml), and washed with 0.5 N ammonium hydroxide (50 ml), water (50 ml), and saturated sodium chloride solution (50 ml). The organic phase is dried (Na SO and concentrated. The resulting oil and anhydrous potassium carbonate (20 g) in chloroform (200 ml) is heated at reflux temperature for 4 hr. The solution is filtered and the filtrate poured onto a column of silica gel (400 g). Elution with ethyl acetate-chloroform (1:3) affords the title compound having m.p. 153 155C. after recrystallization from methylene chloridehexane.

EXAMPLE 29 3-(2,2-Dimethylhydrazino)-3-methyl-2,3-dioxo-4- phenyl-l-pyrrolidineacetic acid ethyl ester (1 l l; R and R CH R H, R CH and R phenyl) By following the procedure of Example 7 but replacing isobutyraldehyde dimethylhydrazone with an equivalent amount of ethyl a-phenylacetoacetate dimethylhydrazone, described in Example 1, then the title compound,m.p. 108- 109c., 1770, 1738, 1700 cm, is obtained.

By following the procedures of Example 27, 28 or 29 and using the appropriate hydrazone of formula 11, acid of formula R X and isonitrile of formula R NC then other compounds of formula III are obtained. Examples of such compounds of formula III are listed in Table 11 together with the hydrazone, acid and isonitrile required for their preparation.

methyl hydra- 31 ethyl acetoacetate dimethyl hydra- 32 ethyl acetoacetate dimethyl hydrazone 33 ethyl acetoacetate dimethyl hydra- 34 3-(piperidinoimino)- butyric acid methyl ester (described in Example 2) dioxol -pyrrolidineacetic acid ethyl ester mp. 112 115C. 3-[N-(dimethylamino)- benzamido]-3-methyl-2,5- dioxol -pyrrolidineacetic acid ethyl ester, m.p. 100 102C. 3-[N-(dimethylamino)- p-nitrobenzamido ]-3- methyl-2 ,5-dioxo-1' pyrrolidineacetic acid ethyl ester, mp. 179

benzoic acid ethyl isocyanoacetate ethyl isocyanoacetate p-nitrobenzoic acid 1 3-[p-chloro-N-(dimethylamino)benzamido]-3-methyl- 2,5-di0X0-l-p rrolidineacetic acid etliyl ester, mp. 123 125C. 3-mcthyl-2,5-dioxo-3-(N- piperidinoformamido l pyrrolidineacetic acid ethyl ester, mp. 89 92C.

p-chlorobenzoic acid ethyl isocyanoacetate formic acid ethyl isocyanoacetate 1 5 l 6 TABLE II Continued Hydrazone Acid of Isonitrile Product of Ex. of Formula II Formula RX (RNC.) Formula III 3(piperibcnzoic acid ethyl iso 3-mcthyl-2,5-dioxo-3-(N- dinoirnino cyanoucetate piperidinobenZamid0)-lbutync acid pyrrolidineacetic acid methyl ester ethyl ester, m.pv 140 36 3-(piperip-nitrobcm ethyl iso- 3-methyl-3-[(p-nitro-N- dinomino)- zoic acid cyanoacetatc piperidino)benzamido]- butyric acid 2,5-dioxo-l-pyrrolidmethyl ester ineacetic acid eth l ester, m.p. 232 235C.

37 3-(morpholino formic acid ethyl iso- 3-methyl-3-(N-morpho imino)butyric cyanoacetate linoformamido)-2,5-dioxoacid methyl l-pyrrolidineacctic acid ester (desethyl ester, m.p. 148 cribed in 149C.

Example 2) 38 3-(morpholinop-nitrobenethyl iso- 3-[p-nitro-N-(morpho imino)butyric zoic acid cyanoacetate lino)benzamido]-3-methylacid methyl 2,5-dioxo-l-pyrrolidineester acetic acid ethyl ester, (described in m.p. 237 238C. Example 2) 39 ethyl oz-phenylformic acid ethyl iso- 3-[N-(dimcthylamino)- acetoacetatc cyanoacetate formamido]-3-methyl-2,5- dimethyl dioxo-4-phenyll hydrazone pyrrolidineacetic acid ethyl ester, m.p. l23- 124C.

EX L 40 chloroform extract is washed with water, dried 3-[N-(Dimethylamino)-p-nitrobenzamido]-3-methyl 2,5-dioxo-l -pyrrolidineacetic acid ethyl ester (1 l 1; R and R CH R p-nitrophenyl, R CH and R A solution of the compound of formula I, N- (carboxymethyl)-3-[N-(dimethylamino)-pnitrobenzamido]-3-methylsuccinamic acid ester (15.74 g, 0.035 mole), described in Example 19, and anhydrous potassium carbonate (15.0 g) in chloroform (100 ml) is heated at reflux for 90 min. After filtering the mixture the filtrate is concentrated. The residue is recrystallized from ethyl acetate to afford the title compound, identical to the product of Example 32.

The title compound is also obtained according to the procedure of this example in which the potassium carbonate is replaced by an equivalent amount of sodium carbonate or sodium or potassium hydroxide.

By following the procedure of this example and using the appropriately substituted compound of formula I in which R represents CHRCOO-(lower alkyl) and R represents CH COO-(lower alkyl) then the corresponding compounds of formula III, for example, those described in Examples 27 to 39, are obtained.

EXAMPLE 41 N-Cyclohexyl-4-( dimethylaminoformamido )-4- methylglutaramic acid (1; R and R CH;,, R CHO, R Cl-l Cl-l COOI-I, R CH, and R cyclohexyl) To 5.10 g (0.015 moles) of the corresponding ethyl ester of the title compound, described in Example 5, in 50 ml. of dry methanol, a solution of 1.68 g (0.030 moles) of potassium hydroxide in 5 ml. of dry methanol is added. The mixture is stirred for 6 hr. at room temperature. The mixture is concentrated under reduced pressure, cooled and rendered acidic (pH 4) with dil. HCl. The resulting gum is taken up in chloroform. The

(MgSO and concentrated. The residue is crystallized from methylene chloride-ether to afford the title compound, m.p. 22l222C.

EXAMPLE 42 N- {[N-(Dimethylamino )-N-(N-formylglycyl)]-DL- 35 valyl}-glycine (1; R and R CH R dethyl COCH NHCHO, R CH(CH R H and R CH COOH) A mixture of N-{[N-(dimethylamino)-N-(N- 40 formylglycyl)]-DL-valyl}glycine ethyl ester (6.618 g,

0.020 moles), described in Example 6, and IN NaOH (30 ml) is stirred at room temperature for min. The solution is cooled, rendered acidic with dilute I-ICI and extracted with chloroform. The extract is washed with brine, dried (MgSO and concentrated. The residue is purified by chromatography on silica gel using methanol-chloroform (8:2) as the solvent system. TI'Ie eluate is concentrated and crystallization of the residue from acetone-isopropyl ether affords the title compound, m.p. l57 158C.

By following the procedure of Examples 41 or 42 other compounds of formula I in which the R or R radical includes an ester may be transformed to their corresponding acids. Examples of such acids prepared in this manner are listed in Table III. In these cases the ester used as starting material is indicated by the example in which it is prepared.

formyl-DL-valyl lphenylalanine.

TABLE Ill-Continued No. o1- Example in Which Starting Material is Prepared Product EXAMPLE 48 A saturated solution of ammonia in anhydrous methanol (100 ml) is added with cooling to N-{[N- (dimethylamino-N-(N-formylglycyl)1 -DL- valyl}glycine ethyl ester (12.81 g) described in Example 6. The mixture is stirred at room temperature for 4 days. The solvent is removed and the residue subjected to chromatography on silica gel. Elution with chloroform-methanol (98 2) affords the title compound which, after crystallization from acetone, has m.p. 165 168C.

In the same manner but replacing N-{[N- (dimethylamino)-N-(N-formylglycyl)]-DL- valyl}glycine ethyl ester with an equivalent amount of N-[N-(dimethylamino)-N-formyl-DL-valyl]-DL- phenylalanine methyl ester (Example 11),

N- {N-[N-(carboxyglycyl)-N-(dimethylamino)-DL- leucyl]} -DL-methionine N-t-butyl ethyl diester (Example 23), or

N-[-(p-amino-N-piperidinobenzamido)cyclohexylcarbonyl]glycine ethyl ester (Example 48), then N-[N-(dimethylamino)-N-formyl-DL-valyl]-DL- phenylalaninamide, m.p. l47-l56C,

N- N[N-(carboxyglycyl)-N-(dimethylamino)-DL- leucyl]}-DL-methioninamide N-t-butyl ester, separated by chromatography on silica gel into lsomer A, m.p. 84 89C and lsomer B, m.p. 80 90C, and

2-[ l-(p-amino-N-piperidinobenzamido )cyclohexanecarboxamido]acetamide, m.p. 198 201C, are obtained, respectively.

EXAMPLE 49 N- {1 -[p-Amino-N- (dimethylamino)benzamido]cyclohexyl-carbonyl} DL-phenylalanine methyl ester (1; R and R =CH R p-aminobenzoyl, R and R (CH and R Cl-l(CH C ,-H )COOCH N-{l-[N-(Dimethylamino)-pnitrobenzamido]cyclohexylcarbonyll-phenylalaninc methyl ester (9.5 g), described in Example 13, in ml. of dry methanol is hydrogenated with 5% palladium on charcoal. Thereafter, the catalyst is collected on a filter pad. The filtrate is concentrated and the residue crystallized from acetone-isopropyl ether to give the title compound, mp. 138 139C.

In the same manner but replacing N- {l-[N- (dimethylamino)-p-nitrobenzamido]cyclohexylcarbonyl}glycine methyl ester (Example 18), or N-{1-[(p nitro-N-piperidino)benzamido]cyclohexylcarbonyl} glycine ethyl ester (Example 25), then (dimethylamino)benzamido]cyclohexylcarbonyl} glycine ethyl ester, m.p. 69 71C, and

N- (l-(p-amino-N-piperidinobenzamido )cyclohexylcarbonyl}glycine ethyl ester, m.p. 92 96C, are obtained, respectively.

EXAMPLE 50 N-[N-(Dimethylamino-N-(isocyanoacetyl)-DL- valyl]glycine ethyl ester (1; R and R CH R COCH NC, R CH(CH R H and R CH COOC H A solution of N-{[N-(dimethylamino)-N-(N- formylglycyl)]-DL-valyl}glycine ethyl ester (4.0 g), described in Example 6, in dry methylene chloride (12 ml) is placed in a 3-neck flask fitted with mechanical stirrer, reflux condenser and drying tube (KOH). Redistilled triethylamine is then added (5.08 ml) followed by dropwise addition of a solution of phosgene in benzene (12 ml. of a 12.5% solution). The mixture is stirred an additional 30 min. at room temperature, the precipitate is then filtered off, the filtrate concentrated under reduced pressure to dryness (at temperature 40). The residue is diluted with anhydrous benzene (40 ml) and filtered once more. The filtrate is evaporated to dryness and the residue purified by column chromatography using silica gel. Elution with benzeneethyl acetate (1:1) provides the isonitrile as a yellow solid. To remove the color the material is dissolved in benzene and the solution is filtered through a short column of alumina (Activity 11). The fractions containing the isonitrile are pooled and the solvent removed at low temperature 40) under reduced pressure the residue is triturated with anhydrous diethylether to give the title compound, m.p. 1l9l20.5C.

By following the procedure of Example 50 but replacing N- {[N-(dimethylamino)-N-(N-formylglycyl)]- DL-valyl} glycine ether ester with an appropriately substituted compound of formula I in which R represents COCH NHCHO, prepared by the procedure of Example 6 or 7, then the corresponding compounds of formula I in which R is COCH NC are obtained. For example, N-{[N-(diemthylamino)-N-(N-formylglycl)]- DL-leucyl} -DL-methionine ethyl ester gives N-[N- (diethylamino)-4-(isocyanoacetyl)-DL-leucyl]-DL- methionine ethyl ester.

We claim:

1. A compound of the formula:

in which R and R each are lower alkyl or R and R together with the nitrogen atom to which they are joined form a piperidino or morpholino radical; R is hydrogen, lower alkanoyl, benzoyl, p-nitrobenzoyl, paminobenzoyl, p-chlorobenzoyl, isocyanoacetyl, N- formylglycyl or N-carbobenzoxyglycylglycyl;

R is lower alkyl, CHR COOR or CH CH COOR" wherein R is hydrogen or phenyl and R is hydrogen or lower alkyl; R is hydrogen or lower alkyl; or R* and R together with the carbon atom to which they are joined form a cyclohexylidene radical; and R is CHR cOY wherein R is hydrogen or benzyl and Y is hydroxyl, lower alkoxy or amino, with the provisos that when Y is hydroxyl then R is hydrogen, that when Y is lower alkoxy then R is lower alkyl and that when Y is amino R is lower alkyl.

2. A compound of the formula:

N N C NHR 2/ 1 n R 11 11 In which R and R each are lower alkyl; R is lower alkanoyl; R is lower alkyl; R is hydrogen or lower alkyl; R is CHR COY wherein R is hydrogen or benzyl and Y is hydroxyl, lower alkoxy or amino.

3. N-[N-(Dimethylamino)-N-formyl-DL- valyl]phenylalanine methyl ester, as claimed in claim 2.

R R CH NCHZCOY l l /N T c o R R R5 in which R R R, R and R are as defined in claim 1 and Y is lower alkoxy.

. UNITED STATES PATENT OFFICE CERTIHCATE OF CORRECTION PATENT NO. I 3,888,840

DATED June 10, 1975 lNVENTOR(S) Amedeo Failli, Verner R. Nelson, Hans U. Immer d M f K. G e It is certified t h gat enfib i m The 8b08 l deflIlfl8d patent and tnat sald Letters Patent are hereby corrected as shown below:

. Column 1, line 15, for "666, read 6 6 Column 2, line 5, for "from" read -form--,

Column 5, line 13, for "Hydraines" read Hydrazines--,

. Column 7, line 53, for "luvulinate" read levulinate--,

Column 8, line 10, for "b.O. read b.p.--,

Column 8, line 18, for "comound" read -compound-,

Column 9, line 35, for (N-formylgylcyl) -Dl-" read (D-L-formylglycyl) --DL--,

Column 10, line 34, for "organge read --orange--,

CHCI CHCI II max 3 read Y max Column 10, line 36, for u 3 -w Column 10-,- Table 1, Example 10, in the c Product of Formula l, for J=7,3H) a J lumn Column 13, line 13, for "benzeneethyl read --benzeneethyl,

Column 16, line 47, for "THe" read --The-,

Column 17, line 18, for (N-formylglyclyl) read (N-formylglycyl) Signed and Scaled this fourteenth Day of October 1975 [SEAL] Attest:

RUTH C. MASON C. MARSHALL DANN Arresting ()fficer Commissioner ofParenls and Trademarks 

1. A COMPOUND OF THE FORMULA:
 2. A compound of the formula:
 3. N-(N-(Dimethylamino)-N-formyl-DL-valyl)phenylalanine methyl ester, as claimed in claim
 2. 4. N-(N-(Dimethylamino)-N-formyl-DL-valyl)glycine ethyl ester, as claimed in claim
 2. 5. N-(N-(Dimethylamino)-N-formyl-DL-valyl)phenylalanine, as claimed in claim
 2. 6. N-(N-(Dimethylamino)-N-formyl-DL-valyl)glycIne, as claimed in claim
 2. 7. N-(N-(Dimethylamino)-N-formyl-DL-valyl)-DL-phenylalaninamide, as claimed in claim
 2. 8. A compound of the formula: 